Landslides phenomena are natural hazards cause each year in the world fatalities and damages to buildings and infrastructures, in Mountains regions. However, the prediction of these with numerical models remains a major challenge for hydrogeologists. Meteorological, geotechnical, geological and hydrogeological properties of the environment must be known in detail to understand the landslide kinematics and make robust predictions according to conceptual models. An example occurs in the neighborhoods of the northern area of the city of Bucaramanga where more than 5.000 people are affected. Based on monitoring with inclinometers and vibrating wire piezometers, the relationship between groundwater systems and mass movements was evidenced in an unconfined aquifer of the Bucaramanga formation in the Northern zone of the city of Bucaramanga, Colombia. To provide a solution, a drainage system with shallow galleries was implemented according to the continuous monitoring of the piezometric levels. Numerical simulations were carried out in FEFLOW with a flexible mesh according to the conceptual and geological model and included unsaturated and saturated conditions in fractured media. The simulations permitted to understand the decrease of piezometric levels and seepage conditions to avoid a future landslide in the zone, complement geotechnical models and improve the safety and their quality of life of the people.
Keywords: FEFLOW, drainage galleries, landslide, monitoring, seepage.